static int set_auto_gain(sensor_t *sensor, int enable, float gain_db, float gain_db_ceiling)
{
uint8_t reg;
int ret = cambus_readb(sensor->slv_addr, BANK_SEL, ®);
ret |= cambus_writeb(sensor->slv_addr, BANK_SEL, reg | BANK_SEL_SENSOR);
ret |= cambus_readb(sensor->slv_addr, COM8, ®);
ret |= cambus_writeb(sensor->slv_addr, COM8, (reg & (~COM8_AGC_EN)) | ((enable != 0) ? COM8_AGC_EN : 0));
if ((enable == 0) && (!isnanf(gain_db)) && (!isinff(gain_db))) {
float gain = IM_MAX(IM_MIN(fast_expf((gain_db / 20.0) * fast_log(10.0)), 32.0), 1.0);
int gain_temp = fast_roundf(fast_log2(IM_MAX(gain / 2.0, 1.0)));
int gain_hi = 0xF >> (4 - gain_temp);
int gain_lo = IM_MIN(fast_roundf(((gain / (1 << gain_temp)) - 1.0) * 16.0), 15);
ret |= cambus_writeb(sensor->slv_addr, GAIN, (gain_hi << 4) | (gain_lo << 0));
} else if ((enable != 0) && (!isnanf(gain_db_ceiling)) && (!isinff(gain_db_ceiling))) {
static int set_auto_gain(sensor_t *sensor, int enable, float gain_db, float gain_db_ceiling)
{
uint8_t reg;
int ret = cambus_readb(sensor->slv_addr, REG_COM8, ®);
ret |= cambus_writeb(sensor->slv_addr, REG_COM8, (reg & (~REG_COM8_AGC)) | ((enable != 0) ? REG_COM8_AGC : 0));
if ((enable == 0) && (!isnanf(gain_db)) && (!isinf(gain_db))) {
float gain = IM_MAX(IM_MIN(fast_expf((gain_db / 20.0) * fast_log(10.0)), 128.0), 1.0);
int gain_temp = fast_roundf(fast_log2(IM_MAX(gain / 2.0, 1.0)));
int gain_hi = 0x3F >> (6 - gain_temp);
int gain_lo = IM_MIN(fast_roundf(((gain / (1 << gain_temp)) - 1.0) * 16.0), 15);
ret |= cambus_writeb(sensor->slv_addr, REG_GAIN, ((gain_hi & 0x0F) << 4) | (gain_lo << 0));
ret |= cambus_readb(sensor->slv_addr, REG_VREF, ®);
ret |= cambus_writeb(sensor->slv_addr, REG_VREF, ((gain_hi & 0x30) << 2) | (reg & 0x3F));
} else if ((enable != 0) && (!isnanf(gain_db_ceiling)) && (!isinf(gain_db_ceiling))) {
array_t *imlib_detect_objects(image_t *image, cascade_t *cascade, rectangle_t *roi)
{
// Integral images
mw_image_t sum;
mw_image_t ssq;
// Detected objects array
array_t *objects;
// Allocate the objects array
array_alloc(&objects, xfree);
// Set cascade image pointers
cascade->img = image;
cascade->sum = ∑
cascade->ssq = &ssq;
// Set scanning step.
// Viola and Jones achieved best results using a scaling factor
// of 1.25 and a scanning factor proportional to the current scale.
// Start with a step of 5% of the image width and reduce at each scaling step
cascade->step = (roi->w*50)/1000;
// Make sure step is less than window height + 1
if (cascade->step > cascade->window.h) {
cascade->step = cascade->window.h;
}
// Allocate integral images
imlib_integral_mw_alloc(&sum, roi->w, cascade->window.h+1);
imlib_integral_mw_alloc(&ssq, roi->w, cascade->window.h+1);
// Iterate over the image pyramid
for(float factor=1.0f; ; factor *= cascade->scale_factor) {
// Set the scaled width and height
int szw = roi->w/factor;
int szh = roi->h/factor;
// Break if scaled image is smaller than feature size
if (szw < cascade->window.w || szh < cascade->window.h) {
break;
}
// Set the integral images scale
imlib_integral_mw_scale(roi, &sum, szw, szh);
imlib_integral_mw_scale(roi, &ssq, szw, szh);
// Compute new scaled integral images
imlib_integral_mw_ss(image, &sum, &ssq, roi);
// Scale the scanning step
cascade->step = cascade->step/factor;
cascade->step = (cascade->step == 0) ? 1 : cascade->step;
// Process image at the current scale
// When filter window shifts to borders, some margin need to be kept
int y2 = szh - cascade->window.h;
int x2 = szw - cascade->window.w;
// Shift the filter window over the image.
for (int y=0; y<y2; y+=cascade->step) {
for (int x=0; x<x2; x+=cascade->step) {
point_t p = {x, y};
// If an object is detected, record the coordinates of the filter window
if (run_cascade_classifier(cascade, p) > 0) {
array_push_back(objects,
rectangle_alloc(fast_roundf(x*factor) + roi->x, fast_roundf(y*factor) + roi->y,
fast_roundf(cascade->window.w*factor), fast_roundf(cascade->window.h*factor)));
}
}
// If not last line, shift integral images
if ((y+cascade->step) < y2) {
imlib_integral_mw_shift_ss(image, &sum, &ssq, roi, cascade->step);
}
}
}
imlib_integral_mw_free(&ssq);
imlib_integral_mw_free(&sum);
if (array_length(objects) > 1) {
// Merge objects detected at different scales
objects = rectangle_merge(objects);
}
return objects;
}
